1. Technical Field
The present invention relates to extension rods and, more particularly, to a multi-function extension rod having an associated socket-coupling and angle-adjusting mechanism. The disclosed mechanism primarily comprises a pressing head and an operating pin wherein by pressing down the pressing head, the operating pin can reciprocate correspondingly to facilitate altering the bending angle of the extension rod and receiving a socket tool thereon.
2. Description of Related Art
One major problem of a current hand tool is not always convenient and accommodative to work in all the operating environments, especially to those in confined operational space and requiring specific operational angles. To solve this problem, an extension rod has been provided for being combined with various socket tools, adapters, socket tools and suchlike to address all kinds of working needs.
For aiding assembly and disassembly of the socket tool to the extension rod, a socket-coupling mechanism, as shown in FIG. 1, is typically provided at a conventional extension rod. According to the drawing, the conventional socket-coupling mechanism of an extension rod 900 is composed of a coupling segment 901, a ball hole 911 provided at the coupling segment 901 and extended perpendicular to the axis of the extension rod 900, a spring 912 installed in the ball hole 911 and a ball positioned in the ball hole 911 and propped up by the spring 912. When a socket tool (not shown) is sleeved onto the extension rod 900 at the end of the coupling segment 901, the edge of the socket tool can push and press the ball 913 so that the ball 913 can subsequently press the spring 912 downward and retracts from the surface of the extension rod 900. Later, when a positioning recess of the socket tool (not shown) is aligned to the ball hole 911, the spring can resile and prop the ball 913 up to appear at the surface of the extension rod 900 again. At this time, the ball 913 is coupled with the positioning recess of the socket tool and therefore the socket can be fastened to the coupling segment 901 of the extension rod 900. Oppositely, to disassemble the socket tool from the extension rod 900, the socket tool can be reversely pulled away from the coupling segment 901 of the extension rod 900 so that the edge of the socket tool presses the ball 913 downward to compress the spring 912 and the ball 913 can retract from the surface of the extension rod 900. Consequently, the socket tool can be disassembled from the coupling segment 901 of the extension rod 900.
However, since the spring 912 is positioned directly under the ball 913, once the ball 913 gets pushed, the ball 913 goes down to compress the spring 912 and retracts from the positioning recess of the socket tool it is currently coupled with. As a result, the coupling between the extension rod 900 and the socket tool comes released. Hence, such conventional socket-coupling mechanism tends to cause the socket tool assembled thereon slip off the extension rod 900 during operation and is not an optimal solution of the socket-coupling mechanism.
On the other hand, an angle-adjusting mechanism, also shown in FIG. 1, may further be equipped to an extension rod 900. For instance, the rear end of the coupling segment 901 may be movably connected to a joint segment 902, which is integratedly formed on the extension rod 900. The joint segment 902 has its front end formed as a joint block 921 comprising a plurality of positioning recesses 922 thereon. A ball hole 931 is provided at the end of the coupling segment 901 adjacent to the joint block 921 and receives a spring 932 therein. A ball 933 is positioned in the ball hole 931 and normally propped out by the spring 932. Further, a semi-annular arm 95 protrudes from the end of the coupling segment 901 and is pivotally fastened to the joint block 921 by means of a pivot 94. Thereby, the spring 932 normally props out the ball 933 to abut against one aligned positioning recess 922 on the joint block 921. When the coupling segment 901 is rotated with respect to the joint segment 902, the edge of the positioning recess 922 pushes the ball 933 to press the ball 933 that in turn compresses the spring 932 inward the ball hole 931, so that the coupling segment 901 can pivot on the pivot 94 with respect to the joint block 921. When a desired angle between the coupling segment 901 and the joint segment 902 is reached and the ball 933 is aligned to another said positioning recess 922, the spring 932 can naturally resile and push the ball 933 out to abut against the corresponding positioning recess 922.
The aforementioned conventional angle-adjusting mechanism faces the same problem as the conventional socket-coupling mechanism. That is, once the ball 933 gets pressed, the spring 932 thereunder is compressed and causes the ball 933 leave the currently coupled positioning recess 922. Thus, during the operation of the extension rod 900, a user must always pay attention to the direction and angle where he/she is exerting his/her force; otherwise, the relative replacement between the ball 933 and positioning recess 922 is liable to occur and the set bending angle of the extension rod 900 is consequently changed.
One attempt to solving these and similar problems seeks to provide an ejector pin assembly that make the ball and the spring configured remotely. An extension rod having an ejector pin assembly, as shown in FIG. 2, is described as an example. The reference numeral 960 denotes an extension rod which has a pin hole 961 disposed axially within one end thereof; a pressing head 962 disposed radially within a hole 963 on the wall of the extension rod 960; a ball 964 disposed in a bore 965 on the wall of the extension rod 960; and an ejector pin 966 disposed within said pin hole 961 capable of reciprocating along the pin hole 961 by compressing a spring 967 under the control of the pressing head 962. The ejector pin 966 further comprises a first seat 968 and second seat 969 which are in succession and corresponding to the position of the ball 964, wherein the first seat 968 is deeper than the second seat 969. Thereby, when a user presses down the pressing head 962, the ejector pin 966 can be driven to move by compressing the spring 967 so that the ball 964 can fall into the deeper seat 968 and disappear beyond the surface of the extension rod 960. By this means, since the spring 967 is not arranged under the ball 964 directly, the spring 967 can never be compressed by force acting on the ball 964 and consequently, the undesired replacement of the ball 964 as described above can be remedied. Though the improved socket-coupling mechanism is nearing perfection, the '476 Application and other prior art extension rods do not provide a corresponding amelioration to an angle-adjusting mechanism.
Hence, the inventor of the present invention strained to develop a multi-function extension rod having an associated socket-coupling and angle-adjusting mechanism that implements a more compact and more efficient structure to allow a user to couple a socket tool on the extension rod and adjust the bending angle of the extension rod easily by a single pressing while the stability of the combination between the extension rod and a socket toll and the set bending angle of the extension rod is ensured.